This used to be an oxymoron. There were no cheap CCD cameras unless you consider "$1,000" cheap. That changed a few years ago with Meade's release of the DSI, the "Deep Space Imager." This started out as a simple, uncooled device that seemed a lot like a webcam to most amateurs—until they used one. Not only did the original DSI, a one-shot color camera, sport a slightly larger chip (5.59mm x 4.68mm) than many webcams, its pictures were much less noisy than those of a modified webcam. This was accomplished by an innovative passive cooling system. There's no Peltier cooler; instead, heat is radiated away by cooling fins on the back of the camera and is kept low to begin with since the camera turns off as many of its heat-generating internal electronic circuits as possible during exposures. Although not nearly as noise free as a cooled camera, the original DSI was capable of producing very pleasing images, as seen in Plate 74, and did it for an unbelievable $300.
The DSI was a huge hit, and Meade continued to work on it, releasing a second camera, a more sensitive monochrome imager, the DSI Pro, and, then, a second generation camera, the DSI II, available both in one-shot color and monochrome ("Pro") formats that featured still larger chips (7.40mm x 5.95mm) and still lower noise. The DSI II goes for a reasonable $600 for either the color or black and white version. Meade's not through with the DSI yet. As this is being written, a DSI III has been announced, which will contain a 10.20mm x 8.20mm CCD chip.
Meade's DSI camera is inexpensive and easy to operate, but is still capable of delivering images of surprising quality.
Meade's cameras made a big splash on the astrophotographyscene, but they are no longer the only game in town in the low-priced category. One very popular manufacturer is the Portuguese company Atik Instruments. Starting out as a webcam modifier, Atik has progressed to the point where they are offering some very sophisticated integrating cameras. They still keep a toe in the low end of the market, however, with their Atik 16IC color and monochrome cameras. At a current price of $645, these CCDs are remarkable values. In addition to a sensitive chip in the same size range as the DSI and II, there's a Peltier cooler and a hardware guider output that will allow the camera to be interfaced to a telescope and act as an autoguider instead of an imaging camera. Atik cameras are easily available in the United States from Adirondack Video Astronomy. Orion (also in the United States) offers a camera similar to the Atik, the Starshoot II. One interesting feature of the Starshoot is that its Peltier cooler is powered by two D-cell batteries. Heretofore, power-hungry Peltiers needed hefty 12vdc power supplies.
Many astro-imagers will say that this is where "real" CCDing begins, with Santa Barbara Instrument Group (SBIG) in the U. S. and Starlight Xpress in the U. K. Both companies produce a range of cameras from the relatively inexpensive to the near professional grade. They are probably most well-known for mid-priced "workhorse" CCDs ($3,000 to $6,000).
Many amateurs start out with an inexpensive SBIG camera and stay with this California company's products forever. There's good reasons for that: quality, value, and performance. SBIG offers one attractively priced entry-level cam that hovers just above the lower price region, the ST-402, a 4.6mm x 6.9mm 657 x 495 chip monochrome camera that goes for $1400. Like all SBIG's CCDs it features a Peltier cooler that is regulated. Many other CCDs, both low priced and more expensive, have coolers that cool continuously. Turn them on and they cool. Turn them off and they stop. The SBIG cameras allow the user to determine a "setpoint" temperature.
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